Poly(2-dimethylamino) ethyl methacrylate (PDMAEMA) with narrow molecular weight distributions were prepared by atom transfer radical polymerizations in this study and were investigated as a CO2-triggered emulsifier for emulsion polymerizations of CO2-responsive poly(methyl methacrylate)(PMMA) core-shell nanoparticles in water. PDMAEMA and PMMA nanoparticles were characterized by 1H NMR, SEM, particle size, UV-vis, GPC, DSC, and Zeta potentials. The results found that the synthesized PMMA nanoparticles were coated with about 15 wt% PDMAEMA and had diameters of about 125 nm. These core-shell nanoparticles exhibited CO2/N2-responsive dispersion/aggregation behavior in aqueous solutions. The CO2-responsive behavior was associated with the tertiary amine groups of PDMAEMA which was on surface of PMMA nanoparticles. Upon bubbling CO2 in aqueous solution, the tertiary amine groups were protonated resulting in hydrophilic and water-soluble PDMAEMA and thus water-dispersible PMMA nanoparticles. Upon bubbling N2 in aqueous solution, CO2 could be removed and the PMMA nanoparticle dispersion reverted to aggregation. A higher molecular weight of PDMAEMA led to a faster CO2-responsive dispersion but a slower N2-responsive aggregation of the PMMA nanoparticles. This newly developed synthetic system offers a highly efficient route for the fabrication of highly effective stimuli-responsive polymer nanoparticles that enable more precise control over the composition, physical properties, and environmentally responsive performance of nanoparticles in aqueous solution.

CO<sub>2</sub>-responsive polymer nanoparticles

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

CO2-responsive polymer nanoparticles

CO₂-responsive polymer nanoparticles